Taxonomic revision of Guaranyperla Froehlich (Plecoptera: Gripopterygidae): unveiling the diversity and complexity of a unique genus

Abstract Guaranyperla Froehlich, 2001 (Gripopterygidae: Plecoptera), endemic to southeastern Brazil, includes three species ( G. guapiara, G. beckeri and G. nitens Froehlich, 2001). This genus remains insufficiently studied due to challenges in collecting adults and limited type-material. Our study addresses unresolved taxonomic issues within the genus, led by incomplete semaphoront series and similarities with the related genus Tupiperla Froehlich, 1969 in the adult stage. Using morphological and molecular data, along with species delimitation analysis, we provide a new diagnosis for the genus and species of Guaranyperla , including the reclassification of Tupiperla barbosai Avelino-Capistrano & Nessimian, 2013. All species delimitation methods based on COI suggest that nearly every Guaranyperla population from streams throughout Southeastern Brazil studied represents a distinct species, thus separating G. barbosai comb. nov. , G. nitens, G. guapiara, G. froehlichi sp. nov ., G. puri sp. nov ., and two other species that were not confidently assigned to any valid species. Additionally, it was possible to associate nymphs and adults of most studied species based on COI. We corroborate the morphological species concept of G. beckeri , and provide redescriptions for G. nitens and G. guapiara . Furthermore, we provide the description of two new species, updated geographical records, and images for all species. Results suggest that the diversity of Guaranyperla is still underestimated and further species descriptions should not rely solely on single semaphoronts or genders. Our study establishes molecular and morphological foundations for future studies on the genus, contributing to a broader understanding of Neotropical Plecoptera biodiversity.